Biblio::Isis(3pm)					User Contributed Perl Documentation					 Biblio::Isis(3pm)

NAME

       Biblio::Isis - Read CDS/ISIS, WinISIS and IsisMarc database

SYNOPSIS

	 use Biblio::Isis;

	 my $isis = new Biblio::Isis(
	       isisdb => './cds/cds',
	 );

	 for(my $mfn = 1; $mfn <= $isis->count; $mfn++) {
	       print $isis->to_ascii($mfn),"
";
	 }

DESCRIPTION

       This module will read ISIS databases created by DOS CDS/ISIS, WinIsis or IsisMarc. It can be used as perl-only alternative to OpenIsis mod-
       ule which seems to depriciate it's old "XS" bindings for perl.

       It can create hash values from data in ISIS database (using "to_hash"), ASCII dump (using "to_ascii") or just hash with field names and
       packed values (like "^asomething^belse").

       Unique feature of this module is ability to "include_deleted" records.  It will also skip zero sized fields (OpenIsis has a bug in XS bind-
       ings, so fields which are zero sized will be filled with random junk from memory).

       It also has support for identifiers (only if ISIS database is created by IsisMarc), see "to_hash".

       This module will always be slower than OpenIsis module which use C library. However, since it's written in perl, it's platform independent
       (so you don't need C compiler), and can be easily modified. I hope that it creates data structures which are easier to use than ones cre-
       ated by OpenIsis, so reduced time in other parts of the code should compensate for slower performance of this module (speed of reading ISIS
       database is rarely an issue).

METHODS

       new

       Open ISIS database

	my $isis = new Biblio::Isis(
	       isisdb => './cds/cds',
	       read_fdt => 1,
	       include_deleted => 1,
	       hash_filter => sub {
		       my ($v,$field_number) = @_;
		       $v =~ s#foo#bar#g;
	       },
	       debug => 1,
	       join_subfields_with => ' ; ',
	);

       Options are described below:

       isisdb
	    This is full or relative path to ISIS database files which include common prefix of ".MST", and ".XRF" and optionally ".FDT" (if using
	    "read_fdt" option) files.

	    In this example it uses "./cds/cds.MST" and related files.

       read_fdt
	    Boolean flag to specify if field definition table should be read. It's off by default.

       include_deleted
	    Don't skip logically deleted records in ISIS.

       hash_filter
	    Filter code ref which will be used before data is converted to hash. It will receive two arguments, whole line from current field (in
	    $_[0]) and field number (in $_[1]).

       debug
	    Dump a lot of debugging output even at level 1. For even more increase level.

       join_subfields_with
	    Define delimiter which will be used to join repeatable subfields. This option is included to support lagacy application written
	    against version older than 0.21 of this module. By default, it disabled. See "to_hash".

       ignore_empty_subfields
	    Remove all empty subfields while reading from ISIS file.

       count

       Return number of records in database

	 print $isis->count;

       fetch

       Read record with selected MFN

	 my $rec = $isis->fetch(55);

       Returns hash with keys which are field names and values are unpacked values for that field like this:

	 $rec = {
	   '210' => [ '^aNew York^cNew York University press^dcop. 1988' ],
	   '990' => [ '2140', '88', 'HAY' ],
	 };

       mfn

       Returns current MFN position

	 my $mfn = $isis->mfn;

       to_ascii

       Returns ASCII output of record with specified MFN

	 print $isis->to_ascii(42);

       This outputs something like this:

	 210   ^aNew York^cNew York University press^dcop. 1988
	 990   2140
	 990   88
	 990   HAY

       If "read_fdt" is specified when calling "new" it will display field names from ".FDT" file instead of numeric tags.

       to_hash

       Read record with specified MFN and convert it to hash

	 my $hash = $isis->to_hash($mfn);

       It has ability to convert characters (using "hash_filter") from ISIS database before creating structures enabling character re-mapping or
       quick fix-up of data.

       This function returns hash which is like this:

	 $hash = {
	   '210' => [
		      {
			'c' => 'New York University press',
			'a' => 'New York',
			'd' => 'cop. 1988'
		      }
		    ],
	   '990' => [
		      '2140',
		      '88',
		      'HAY'
		    ],
	 };

       You can later use that hash to produce any output from ISIS data.

       If database is created using IsisMarc, it will also have to special fields which will be used for identifiers, "i1" and "i2" like this:

	 '200' => [
		    {
		      'i1' => '1',
		      'i2' => ' '
		      'a' => 'Goa',
		      'f' => 'Valdo D'Arienzo',
		      'e' => 'tipografie e tipografi nel XVI secolo',
		    }
		  ],

       In case there are repeatable subfields in record, this will create following structure:

	 '900' => [ {
	       'a' => [ 'foo', 'bar', 'baz' ],
	 }]

       Or in more complex example of

	 902   ^aa1^aa2^aa3^bb1^aa4^bb2^cc1^aa5

       it will create

	 902   => [
	       { a => ["a1", "a2", "a3", "a4", "a5"], b => ["b1", "b2"], c => "c1" },
	 ],

       This behaviour can be changed using "join_subfields_with" option to "new", in which case "to_hash" will always create single value for each
       subfield.  This will change result to:

       This method will also create additional field 000 with MFN.

       There is also more elaborative way to call "to_hash" like this:

	 my $hash = $isis->to_hash({
	       mfn => 42,
	       include_subfields => 1,
	 });

       Each option controll creation of hash:

       mfn Specify MFN number of record

       include_subfields
	   This option will create additional key in hash called "subfields" which will have original record subfield order and index to that sub-
	   field like this:

	     902   => [ {
		   a => ["a1", "a2", "a3", "a4", "a5"],
		   b => ["b1", "b2"],
		   c => "c1",
		   subfields => ["a", 0, "a", 1, "a", 2, "b", 0, "a", 3, "b", 1, "c", 0, "a", 4],
	     } ],

       join_subfields_with
	   Define delimiter which will be used to join repeatable subfields. You can specify option here instead in "new" if you want to have per-
	   record control.

       hash_filter
	   You can override "hash_filter" defined in "new" using this option.

       tag_name

       Return name of selected tag

	print $isis->tag_name('200');

       read_cnt

       Read content of ".CNT" file and return hash containing it.

	 print Dumper($isis->read_cnt);

       This function is not used by module (".CNT" files are not required for this module to work), but it can be useful to examine your index
       (while debugging for example).

       unpack_cnt

       Unpack one of two 26 bytes fixed length record in ".CNT" file.

       Here is definition of record:

	off key        description			       size
	 0: IDTYPE     BTree type			       s
	 2: ORDN       Nodes Order			       s
	 4: ORDF       Leafs Order			       s
	 6: N	       Number of Memory buffers for nodes      s
	 8: K	       Number of buffers for first level index s
	10: LIV        Current number of Index Levels	       s
	12: POSRX      Pointer to Root Record in N0x	       l
	16: NMAXPOS    Next Available position in N0x	       l
	20: FMAXPOS    Next available position in L0x	       l
	24: ABNORMAL   Formal BTree normality indicator        s
	length: 26 bytes

       This will fill $self object under "cnt" with hash. It's used by "read_cnt".

BUGS

       Some parts of CDS/ISIS documentation are not detailed enough to exmplain some variations in input databases which has been tested with this
       module.	When I was in doubt, I assumed that OpenIsis's implementation was right (except for obvious bugs).

       However, every effort has been made to test this module with as much databases (and programs that create them) as possible.

       I would be very greatful for success or failure reports about usage of this module with databases from programs other than WinIsis and
       IsisMarc. I had tested this against ouput of one "isis.dll"-based application, but I don't know any details about it's version.

VERSIONS

       As this is young module, new features are added in subsequent version. It's a good idea to specify version when using this module like
       this:

	 use Biblio::Isis 0.23

       Below is list of changes in specific version of module (so you can target older versions if you really have to):

       0.24    Added "ignore_empty_subfields"

       0.23    Added "hash_filter" to "to_hash"

	       Fixed bug with documented "join_subfields_with" in "new" which wasn't implemented

       0.22    Added field number when calling "hash_filter"

       0.21    Added "join_subfields_with" to "new" and "to_hash".

	       Added "include_subfields" to "to_hash".

       0.20    Added "$isis->mfn", support for repeatable subfields and "$isis->to_hash({ mfn => 42, ... })" calling convention

AUTHOR

	       Dobrica Pavlinusic
	       CPAN ID: DPAVLIN
	       dpavlin@rot13.org
	       http://www.rot13.org/~dpavlin/

       This module is based heavily on code from "LIBISIS.PHP" library to read ISIS files V0.1.1 written in php and (c) 2000 Franck Martin
       <franck@sopac.org> and released under LGPL.

COPYRIGHT

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

       The full text of the license can be found in the LICENSE file included with this module.

SEE ALSO

       Biblio::Isis::Manual for CDS/ISIS manual appendix F, G and H which describe file format

       OpenIsis web site <http://www.openisis.org>

       perl4lib site <http://perl4lib.perl.org>

perl v5.8.8							    2007-05-18							 Biblio::Isis(3pm)